Switch



Dec. 5, 1933. I H, c;- KALwlTz 1,937,701 SWITCH v Filed Jan. 11. 1952 2 sheets-sheet .1-

H C. KALWITZ Dec. 5, 1933.

SWITCH Raga.

Patented Dec. 5, 1933 SWITCH Herman C. Kalwitz, Chicago, Ill.

Application January 11,v 1932. SeralNm 585,861

` Claims.

This invention relates to high voltage switches in general and more particularly to disconnect switches such as are adapted to be immersed. in an oil bath. In its more specific aspect the 5 switch of the present invention constitutes an improvement on the disconnect switches shown in Figs. 6 and 7 of my pending patent application Serial No. 479,624, filed September 4, 1930.

In my above referred to vapplication I show a metal clad substation wherein all of the parts are immersed in oil. Eachdisconnect switch is mounted in an oil tank and so rarranged that a grounded barrier is moved between the terminals as the switch is opened. This is a feature necessary Vfor the safety of the operator when the operator inspects or repairs the switch. When the switch is closed 'the grounded barrier is located above the switch at a dis'- l tance determined by the insulation requirements. When the switch is opened the barrier moves downward between the contacts. Since compactness is one of the prime virtues H fof the metalclad switch gear it is apparent u that the switch housingk or casing cannot be made so large as to encompassy the barrier. The casingis therefore provided with an extension intowhich the barrier protrudes when the switch is closed and from which it is projected when the 3 switch is open. This extension increases the cost of the switch. `It is an object of the presentl invention to eliminate the need for this extension. I propose vto accomplish this end by making the barrier as a unit separate from the switch proper and adapted to be inserted into the switch casing when the switch is open and removed therefrom prior to closure of the switch. f

One of the reasons for interposing a grounded barrier between the two switch terminals is that it permits the safe inspectionand rrepair of either one of the terminals while the other terminal is at its normal line voltage. -The distance between each terminal and the grounded barrier must 'therefore be such astoafford adequate insulation between the live terminal and ground. If the arrangement is such that the draining of the oil surrounding one terminal necessarily results in or requires the draining of the oil surrounding the other terminal then the minimum allowable distance between the terminal and the grounded barrier must be gured on the basis of air as the insulating medium. I propose tov make the arrangement such that the barrier forms a liquid tight seal with the bottom and sides of the switch casing thus dividing the casing into two parts either one of which may be drained of its oil while leaving the other full Vof oil. By this arrangement the oil may be drained from the side of theswitch that is to be inspected or repaired and which is therefore at ground potential, while the other terminal, which Vmay be at the line potential, is immersed in oil. The spacing requirement between the live terminal and the grounded barrier is thus reduced, thereby reducing the overall size of a switch for a given voltage system.

The top of the switch casing is provided with an opening through which thek barrier may be inserted. A closure is provided for the opening, said closure being interlocked with the switch to prevent openingof the closure when the switch is closed. If desired the interlock may be arranged 'to prevent reclosing of the switch when the closure is in its open position. This however is generally not necessary. The barrier is adapted to be inserted into position when the closure is open and is itself provided with an arrangementfor completelyvclosingthe barrier receiving opening in the casing.

'Ihe barrier comprises, preferably, a metallic plate provided with means for making good electrical contact with the sides of the casing, which is grounded, thus assuring a grounding of the barrier. Various arrangements ymay be provided for making a liquid tight sealL between the barrier and the casing. A simple arrangement consists merely of a rubber tube, similar to an inner tube of a pneumatic tire, placed around the barrier and adapted to be inated `after the barrier has been inserted into the switch casing. Upon inflation of the tube it is expanded into rm contact with the adjacent walls of the kcasing to Vrform a liquid tight seal. As an alternative a solid rubber or leather rim may be used, the rim being made of a somewhat wedge shape to form a liquid tight seal as the barrier is inserted into place.

The attainment of .the above and further objects of the present invention will be apparent from the following specication taken in conjunction with the accompanying drawings form- 10'5 ing a part thereof.

In the drawings: y Figure 1 is a fragmentary transverse sectional view through a switch embodying the principals of my invention;

VsameV purpose.' 'It is to be noted that the Figure 2 is a fragmentary top view thereof with the cover removed; Y

Figure 3 is a View similar to Figure 1 and showing the switch in its open position with the separating barrier inserted in place;

Figure 4 is a sectional View taken along the line 4--4 of Figure 3 and looking in the direc tion oi the arrows; and

Figure 5 isa front view of the removable barrier.

The switch of the present invention is particularly adapted for use in an oil iilled Vbus switching station of the type disclosed inmy pending' application, Serial No. 479,624, iiled September 4, 1930, the present switch Vcorrespondingto the Aswitch shown in Figures 6 and 7 of that application, The switch is mounted in an oil casing 1 which also constitutes a terminal bor: and

which isz. provided with bottom, sideend and` top walls comprising an oil tight box. In switches that are adapted vforA use on medium Vhigh voltage systems the top is made in two parts, separately removable to permit "inspection or repair of theswitch within. In switches that are designed for use on higher voltages the top vis providedwith a plurality of covers correspondthis dissyscan

ving to' man-hole covers for accomplishing connect switches vused on very high voltage tems are 'frequently so large thata man Henter'into the switch casing through the cover.

The switch proper which is mounted. within the casingv 1 may be of any preferred construction and Vis here vshown as an ordinary knife switch comprising al terminal or contact 2 mounted on an insulator 3 and having a blade 4 'pivoted thereonand adapted tobe receivedV between'a pair ofV jaws of a terminal clip or con- -tact 5 which is mounted upon an insulator 6.

The switch is adapted to beoperated by means of a lrotatable shaft 7 onY which is keyed a crank 8, and a connecting rod 9 of suitable insulating material;k A conductor 10 which extends the circasing in a similar manner.

`The casing 1 is grounded and is providedwith a terminal clipl'? for receivingthe free end of the blade 4 when the blade is moved to its normal switchopen position, thereby grounding the 'terminal clip 2 and the'line conductor 14.

. The top of'the'switch casing is provided with an opening 20 which extends for the full width of the casing and is dene'd by a pair of oppo-k sitelyffacing flange members 21-21. The opening 20 is provided with a cover 22, hinged at 23 and adapted to be swung over the ,members 21-21 and form a closure for the opening 20.

vAn interlock is provided for preventing opening of the cover 22 Awhen the disconnect switch is in its closed position. This interlock .comprises a slidable rod 24 carried on suitable brackets on the underside of the cover l and adapted toy enter an opening in a depending member 25 secured-to the cover 22. When the switch is in its closed position the rod 24 engages the opening inthe member 125 and prevents opening of the cover 22. When thepswitch is moved to its open position the blade engages a projection 27 on the rod 24 and moves the rod out oi engage? mentwith ,the member25.

When the switch blade is again moved to its closed positionit engages a member 28 on the rod 24 and thus moves the rod to Yitsrrlocking position. Ii the switch is moved to its closed position before the opening 20 has been closed it becomes impossible to thereaiterswing the cover to its closed position, whereby the operator is apprised of this fact.- 1i an attempt is made to close the switch Vwith the cover 22 partly closed the rod 24 will abut against the member 25 and being thereby held against further movement it holds the blade against closure, thereby apprising .the operator o the fact that the cover is not correctly closed.

The switch casing 1 is adapted to receive a barrier through the opening 20vvwhen the blade is in its open position. For this purpose a channel guidcway is provided along the side walls adjacent the opening and along the bottorn'wall.

Thischannel guideway. comprises two angle iron members 3ft-o secured to each side wall in spaced relation and extending downwardly irom the k'opening 20 on the innerside of said wall. A similar pair or" angle iron members 31-31 are securedto the bottom wall oi the casing 1.

frV barrier, such asis illustrated in Figure 5, is provided for the purpose of dividingthe switch housing into two separate sections. The barrier is separate from the switch and is adapted to be inserted therein when the switch has been operated to its open position. The barrier comprises arnetallic plate 35 oi a generally rectangular cross section and provided with a tube of rubber or the like along its outer periphery. The tube is indicated at 36 and is of a construction substantially'similar to that of the inner tube used in pneumatic automobile tires. A valve stem V3'7 communicates ywith the tube Vand is adaptedto receive the end of an air pumpor the like for the purpose of inflating the tube 36. The valve 37 extends throughany openingin a cover-member 38 secured to the plate 35; iResilientmetallic strips 40 are secured to one sidelof Vthe plate 35 and along'the periphery thereof. These strips are adapted toY engager the angle iron members 30`31 within the switch casing forgrounding the plateV 35 when the barrier is inserted intothe casing. 'f 1 When it is desiredto inspect the disconnect switch, or to repair thesame, the .circuit through the disconnect switch is opened at some point other than the switch and the'switch blade is thenrswung to its open position. 'Thereafter the cover 22 is opened and the'barricr shown in Fig-V ure 5 is inserted` into the casing through the openingv 2e. At this time the tube 36 is deflated and the barriervilts not too tightly within'the channel donned by the angle lmembers 30;-30 and 31e-.31. The cover 33 which isa part of kthe barrier fits yover` the members 21--21 thereby closing the'opening 20. To facilitate the handling of the barrier the cover r3S is provided with a pair or" handles indicated at 4l-41. Upon inflation of the tube the resulting Vexpansion produces a liquid tight seal between the rubber tube and the wall of the switch casing. At this time the flexible metal strips'40 are forced into firm electrical contact with the angle members 30 by the pressure within the tube thus producing a good ground connection It is now possible to dr n the oil trom either half oi the switch casingrwhile maintaining the other half of the casingrfull of oil. `Assume. that the right hand hah of the casing is drained of noV to the 'metal 35.

applied to a switch whereinthe-blade is ground- :its oil While the vleft hand half lis maintained -fulliof oil.` This meansthat'the contact 5 is still `immersed in its oil bath Yanditherefore there is suitable insulation between this contact and the walls of the housing'and also betweenthis contact and the grounded `barrier plate 35, even always necessary lto drain the oill from one of the It is frequently sectionsof the switch housing. possible to inspector repairvarious parts of the switch while they same `areimmersed in oil. This may be done withsafety when the barrier .is'in position, even though `the other terminal is at line potential. This is so because the plate 35 is grounded.

`While Il have herein shown my invention as ed when the switch is-fopen it is of course to be understood ythat the invention is not limited to v'such an arrangement since the grounding contact`17 may be omittedwllere necessary. Under such circumstances the contact L2 may bealive Aat the time the switch blade is in its open position whereasthe contact 5 may be at ground potential lbecause of the -establishment of a ground connection to the conductor at some remote point. In such an arrangement either of the contacts may be at line potential and immersed in its insulating oil while the other Contact is at ground potential and free of its insulating oil for inspection or repair purposes.

While I have herein shown one particular arrangement for obtaining a liquid tight seal or closure between the two halves of the switch housing it is to be understood that other means for obtaining this same result may be used. For instance, instead of resorting to ination of the tube 36 for producing this seal the equivalent effect may be obtained by providing a rubber or leather rim around the plate for producing a wedging action within the channel defined by the angle members 30-30 and 31-31. Likewise, other equivalent arrangements may be used.

In compliance with the requirements of the patent statutes I have herein shown and described a preferred embodiment of my invention. It is however to be understood that the invention is not limited to the precise arrangement herein disclosed, the same being merely illustrative of the principles of the invention. What I consider new and desire to secure by Letters Patent is:

1. A switch comprising a housing, a pair of terminals therein and a switch member movable into and out of bridging relation with the terminals, said housing having an opening extending transversely across the top between the two terminals, a closure for the opening, barrier receiving guideways along the inner sides of the housing at the opening for receiving a barrier between the terminals, and a barrier insel-table into the housing through the top thereof and engaging said guideways, said barrier having a pneumatic tube along at least a portion of the periphery thereof adapted to be iniiated to form a liquid tight seal between the barrier and the wallsof the housing.

' 2. A switch comprising a housing, a pairo terminals therein and a switch membermovable into and out of bridging relation with the terminals, said .housing having an openingv extending transversely across the top between the two terminals, a closure for the opening, barrier :receiving guideways along the inner sides of the housing at the opening for receiving a 'barrier between' the terminals, and a barrierfinsertable into the vhousing through the top thereof 'and engaging/said"guideways, saidV barrier havingV a pneumatic tube alongat least a portion ofthe periphery thereof adapted to be 'inflated to form a liquid tight Aseal between kthe barrierand the walls of thel housing, said barrier including a portion at the top thereof adapted to; form a closure for the top opening in the housing.

3. An oil switch including an oil containing casing; Aapair of spaced switch terminals mount- ;ed therein, a` switch `blade movable into andV out of bridging relation to the terminals, a barrier movable between the terminals when the blade is in its open position, said barrier y dividing the casing into two' parts and making a liquid tight seal with the walls of the f casing to .permit emptying'of one'part ofthecasing while maintaining -the oil filled condition of thefother part.

4. An oil switch including an 'oil casing, ra pair of relativelymovable contactfmaking members adapted to be moved'into and out of engagement, and a barrier movable betweenwthe kcontact making members and forming a liquid tight seal with the walls of the casing.

5. A disconnect switch comprising two terminals and means for establishing andr disestablishing a connection between them, a housing for the members, said housing having an openingat the top thereof, and a grounded-barrier removably inserted through the opening and extending between the terminals and including a closure for the opening.

6. A disconnect switch comprising two terminals and means for establishing and disestablishing a connection between them, a housing for said terminals adapted to contain liquid insulation, and a grounded metallic barrier movable into a position between the terminals and contact with said housing to form a liquid tight seal between thep'ortions of the housing on opposite sides of the barrier.

9. A barrier for insertion into a switch housing to divide the same into two hydraulically separate compartments, said barrier comprising a metallic plate having a rubber lining memf ber along the major portion of its periphery and strips of spring metal secured to the plate adjacent the edges thereof and adapted to make electrical contact with al switch housing to ground the plate when the barrier is inserted into a switch housing.

10. A switchv including cooperating switch terminals, a housing for the terminals, said housing having an opening at the top thereof, a closure for the opening, kand a grounding barrier carried by the closure and extending between Athe terminals, whereby the presence of wthe `closure indicates the-presence of the grounded barrier .between the terminals.

11. A switch including cooperating switch terminals, ahousing for the terminals, said housing having an opening at the topfthereof, a closure vfor the opening, a grounded barrier Y carried bythe closure and extending v,between the terminals, whereby the presence of the closure indicates the presence of the grounded barrier between the'terminals, andvrmeans for preventing the fully movement ofv the barrier into the housing kwhen theswitch is closed and preventing the closing of the switch when the barrier is in position. Y 1

12. A switch .including a pair ofswitch terminals, a housing therefor, said housing having an opening at the top thereof, a closure for the opening, means forpreventing opening of the closure when the switch is closed, a second closure for the opening adapted to be usedwhen the 'rst closurefis in its open position, andmeans for preventing rclosing `of the switchwhen the second closure is over said opening.

13. A switch including a pair ofV switch terminals, a housing therefor, said housing having an opening at the top thereof, a closure for the opening, -meansforpreventing opening of the closure when the switch is closed, a second closure, forthe opening adapted to be used rwhen `theflrst closure is in-its Vopen position, and

means f or preventing closing of the yswitch when the second closure is over said opening, the two named preventing means including'a common actuatingfrod actuated by theswitch.

15. A switch including a pair ofy switch rter,-

minals, means for bridging the terminals, a

housing for the terminals, said housing having an opening, lclosure means rfor' the opening, means for preventing opening of theV closure means Vwhen the switch is closed, grounding means movable through Athe opening into position between the terminals when the switch -is open and insulatedfrom at least one of the terminals, and means for locking the switch against substantial lswitch closingr movement when the grounding means is in positionV between the terminals.

HERMAN C, KALwrrz." 

